Morgan Pressel leads LPGA Championship heading into a 36-hole Sunday

Morgan Pressel slogged through rain and muck to take the lead Saturday after two rounds in the LPGA Championship in Pittsford, N.Y. Next up is a 36-hole marathon Sunday.

‘‘I run a lot,’’ Pressel said, laughing. ‘‘I'm in plenty good of enough shape to get through 36 holes tomorrow.’’

She shot a 2-under 70 on Saturday at Locust Hill to reach 6-under 138 — two shots ahead of top-ranked Inbee Park and Chella Choi in the second LPGA Tour major of the season.

Park had a 68 to give herself an opportunity to add to her three wins already this season, including the Kraft Nabisco Championship in April. Choi struggled with a 73 to relinquish her first-round lead.